The instant invention relates to a paraffining device. Such a paraffining device is known from DE 34 22 814 A1 for example. In the known paraffining device, a yarn to be covered with a layer of paraffin runs over a fixed paraffin piece which is mounted rotatably, the axle of rotation being perpendicular to the running direction of the yarn. The arriving yarn is guided over the front of the paraffin piece so that a thin coat of paraffin on the yarn results. In order to ensure even coating, care is taken for the paraffin piece to remain always in the same position in relation to the course of the yarn, even when it becomes smaller due to the removal of paraffin. To ensure this, the paraffin piece is mounted on its axle of rotation so that it can be shifted. A stop is provided here by which the paraffin piece is pressed in the direction of the yarn by means of a spring. The contact between the yarn and the paraffin piece takes place on the front of the latter. Due to the fact that it rotates slowly around an axle that is perpendicular to the direction in which the yarn runs, the front of the paraffin piece is given a convex surface. As appears from DE 34 22 814 A1, paraffining devices are used also on bobbin-producing machines, in the immediate proximity in front of the yarn wind-up. In rotor spinning machines for example, where fiber sliver coming out of a presentation can is twisted into a yarn by means of a spinning rotor, the paraffining device is located between the rotor box in which the yarn is twisted and the winding device.
In paraffining the yarn, paraffin is removed from the paraffin piece through friction, whereby smaller or larger paraffin particles are rubbed off depending on the hardness of the paraffin piece and which do not adhere to the yarn but leave the area of the paraffining device in the form of free paraffin particles which cause malfunctions in the textile machine. Also, paraffin which has already been applied may be rubbed off again at yarn deflection points, in particular if these are located directly within the yarn course following the paraffin clump. These free paraffin particles cause the spinning or winding device to be soiled. This soiling may lead to disturbances of the spinning and winding process. For example, these free paraffin particles may enter the presentation cans together with the presentation sliver on open-end spinning machines. Thereby they continue into the yarn-forming zone of the rotor where they may cause interference in the yarn forming process and even yarn breakage.
With rotor spinning machines in particular, it was found through experience in the past that in the production of yarns out of a given starting material an increased number of yarn breakages occurred during paraffining, with considerably adverse effect on the economy of yarn production. Yarns made of viscose in particular were not paraffined on rotor spinning machines for this reason. When a presentation sliver of pure cotton was used however, no significant errors in the yarn formation were found with the same paraffining device. It has now been found that the free paraffin particles which reached the presentation can are responsible for this.